Low 750ss oil pressure problem

#1

Hi to everyone. New member with a few Ducs but getting down to one with a problem straight away .
Ok I purchased a 750ss last winter from a guy who seemed chatty and genuine when I viewed the bike , It started and ran fine , it was cold and the oil light went out fine when revved and when the revs dropped stayed out , the engine sounded ok , so with only 18500 on the clock I went ahead and purchased the bike .
It started and ran fine , I never rode the bike as was in a built up area and but trusted the guy as he said he would ride it the 5 miles to mine when I bought it .
On dropping the bike off and collecting the money his manor was different and was off like a shot . I ran the bike up the rd now in a rural area and discovered now it was hot the oil light came on once you knocked the throttle off and the revs dropped to about 2500 revs.
I know a little bit about engine so started doing all the relavent checks . I swopped the pressures switch’s over with one of my 748’s and it made no difference, I purchased an oil pressure gauge and trying that . The pressure was almost non exsistant when cold and revved I think just about made 5 and non revving was lucky to reach 1.5 .
Way below the hand book recommendations.
To check the pressure kit I swopped it to one of my 748’s that was spot on .
I had already changed the oil using the correct grade oil and filter , cleaned the screen filter , checked the pressure release valve so resolved to checking the pump . The gap between the gears was a little big so replaced the pump with still no difference.
I resolved to stripping the motor , to which I am now about to split the cranks to check the mains . I have found nothing with excessive wear up till now and am now worried if I check the mains and the fine were to start looking on the rebuild . I will have the mains done anyway so will be looking for a good machine shop .
Sorry if I’v gone on a bit . Any help would be much appreciated.
Nice to meet you all .
Regards Brian

#2

Hi did you check the compression? it could be worn rings or valve guides
Cheers Andy

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#3

No Andy . I possibly should have done . There was no oil smoke or noise . I was going to have an engineer check the pistons and replace the rings anyway .
Do you know of any good trustworthy engineering company’s.
Cheers Brian